Untersuchungen zu dem Einfluss von Verarbeitungstechniken lichthärtender Komposite auf polymerisationsbedingte Spannungen in Modellkavitäten

In opposite to amalgam, composites became more and more significant in the last years. Beside many vantages, the composite fillings are leaning to gap formation. The gap formation is the consequence of polymerization shrinkages of the composite materials. It was attempt through enhanced adhesive techniques to working against the polymerization-shrinkage and to optimize the compound between composite and dentin. But the optimized compound increased the stress charge through the shrink strength on the adhesive surface. To work against the failure of adhesive systems through increased charge, the laminating technologies are evolved to the standard in the last years. The purpose of this study was to visualized, about a special optical method, the stress in model-cavity (V=112mm3, C=0.92) in usage of stress optical pictures. On this way it is possible to compare the accruing stress in the model-cavity material on different filling methods. The bulk-filling, the increment-filling and a new technique, a small volume light-insert (V=8,6mm³) which was pre-exposed in bulk-fillings, are examined. Arabesk TOP and a experimental nano-composite of VOCO was used as filling materials. A halogen lamp (850mW/cm²), a plasma-lamp (790mW/cm²) and a blue solid state laser (488nm/16mW) are substituted for polymerization. The results offer the highest stress evaluation on bulk-fillings. The incremental fillings reduced the stress significant. The light-inserts for bulk-fillings, as a new method, offer equivalently results like incremental-fillings. The substituted light sources having significance for the evolution of polymerisation stress. The visualized optical method allowed the presentment of stress in model-cavity, in such a way to compare different filling- and processing techniques relating stress evaluation. It could to prove experimental a stress reduction through incremental fillings. That is in opposition to the theory of Versluis 1998. The stress reducing effect of the new used small volume light inserts are interpreted as a efficient 3D soft-start technique for polymerization.